Abstract: With the deepening of the national“30/60 dual-carbon”goal,the country has put forward higher requirements for carbon emission reduction of coal-fired units,therefore,more coal-fired units will be retrofitted for heating in the future. In order to meet the technical needs of converting coal-fired units to heating units,based on the analysis of the characteristics of 4 supercritical coal-fired units in a power plant and the demand for ultra-high heating load,two transformation schemes are proposed. The first transformation scheme is to dismantle the original steam turbine of the unit and install a small steam turbine for the power plant. The auxiliary equipment is powered,and the steam parameters are adjusted by the desuperheater and pressure reducer to meet the user’s needs. The second transformation plan is to build a new generator unit with the same parameters,remove medium and low pressure cylinder of the steam turbine,and retain high pressure cylinder of the steam turbine and high-pressure heater and low-pressure heater of recovery system of the original unit. The low-pressure heater,deaerator and No. 3 high-pressure heater steam extraction of the original unit come from the medium and low pressure cylinders of the new unit;on the other hand,in order to reduce the coal consumption of the new unit,the reheated steam of the original unit is used to heating feed water,main steam or reheat steam for the new units. The heating capacity and system exergy efficiency of the two transformation schemes are calculated,the calculation results show that although the 1st scheme is simple to transform and has a small investment,the unit is basically transformed into a steam boiler after the transformation,so the system exergy efficiency is less than 35%;although the system of the 2nd scheme is relatively complex,the investment cost is high,and the reliability requirements of the unit are also high,however,the exergy efficiency of the system is high and the power supply is large. After the transformation,the exergy efficiency of the system of the 2nd scheme can reach45. 3%,and the power supply can reach 1 704. 56 MW. Therefore,the research results can provide a good choice for the heating technical transformation of the power plant,and can also provide a technical reference for similar technical transformations in the future.